This is a Kyrielle, inspired by recent research which has developed a new method for tracing the amount of urine that is present in public swimming baths.

The researchers found that the artificial sweetener, acesulfame potassium (ACE), is an excellent tracer for urine, as it is widely consumed, chemically stable, and is completely excreted by humans in their urine. As ACE is not a naturally occurring product, this means that if any of the substance is detected in the swimming pool it is there because it has been excreted into the pool during urination.

An analysis from 31 pools across two different Canadian cities found ACE in all the measured samples, meaning that urine was present in ALL the pools. Urine is dangerous because the urea (an organic compound) that it contains can react with the chlorine in the pool to create Disinfection By-Products (DBPs), which in turn can cause eye irritation and respiratory problems. This research is important because it provides a novel method for measuring the amount of urine that is in a pool (via the ACE tracer), and can be used to help drive education initiatives to improve pool hygiene standards.